In recent years, in a semiconductor manufacturing process, further improvement in fine processing technology has been required according to higher integration or higher performance of an element. In the semiconductor manufacturing process, etching technology is an important one among fine processing technologies. In recent years, among etching technologies, a plasma etching technology which can achieve high efficiency and enable fine processing of a large area has become mainstream.
The plasma etching technology is one of a dry etching technology. In the plasma etching technology, a mask pattern is formed by a resist on a solid material, that is an object to be processed, and in a state where the solid material is supported in a vacuum, a reactive gas is introduced into the vacuum. Then, a plasma state is made by collision between accelerated electrons and gas molecules due to a high-frequency electric field applied to the reactive gas. Radicals (free radicals) and ions, which are generated from the plasma, react with the solid material which is exposed from the mask pattern, and whereby the exposed solid material is removed as a reaction product. In this way, a fine pattern is formed in the solid material.
On the other hand, there is a plasma CVD method, as one of thin film growth technology in which source gases are combined by the action of plasma and the obtained compound is deposited on a substrate. This method is a film formation method in which plasma discharge is caused by applying a high-frequency electric field to gas which includes source molecules, then, the source molecules are decomposed by electrons accelerated by the plasma discharge, and the obtained compound is deposited. Even if it is reaction which does not occur by only thermal excitation at low temperature, since in plasma, gases in a system collide with each other and are activated, thereby being turned into radicals, reaction becomes possible.
In a semiconductor manufacturing apparatus using plasma, such as a plasma etching apparatus and a plasma CVD apparatus, in the past, an electrostatic chuck device has been used as a device to easily mount and/or fix a wafer onto a sample stage and also maintain the wafer at a desired temperature.
As such an electrostatic chuck device, for example, an electrostatic chuck is proposed which includes an electrostatic chuck section comprising an internal electrode for electrostatic adsorption, and a cooling base section which cools the electrostatic chuck section. A heater which is formed by a screen printing method and having a thickness of 0.5 mm or less is provided between the electrostatic chuck section and the cooling base section, and the heater is brought into direct contact with the electrostatic chuck section and also fixed to the cooling base section by an adhesive layer which has insulation properties and is formed of silicone resin (Patent document 1).
In addition, an electrostatic chuck device is also proposed which includes an electrostatic chuck section comprising an internal electrode for electrostatic adsorption, a temperature adjustment base section which adjusts the temperature of the electrostatic chuck section to a desired temperature, and an organic adhesive layer which integrates the electrostatic chuck section and the temperature adjustment base section by adhesion and includes a thin plate-like heater element made of nonmagnetic metal having a thickness of 200 μm or less (Patent document 2).